This invention relates to the pasting of foraminous grid substrated with viscous electrochemically active paste, and more particularly to the fabrication of thin, flexible, pasted lead-based electrode plates suitable for use in normally sealed, preferably spirally wound lead-acid batteries.
Conventional lead-acid pasters employ an open-air vertical feed gear pump which injects paste into the usual cast lead rigid grid moving horizontally under the gear pump. Doctor blades are normally employed to scrap off excess paste. This type of system has not been found suitable for accurately pasting relatively pure lead grids, which are generally soft and flexible. Pasting systems which have been found suitable for metering and applying viscous, preferably thixotropic lead-based pastes onto soft deformable lead grids are taught in U.S. Pat. Nos. 3,814,628 to Larkin and 3,894,886 to Pankow et al. In these patents a single cavity discharge nozzle is disposed on one side of the grid and applies a ribbon of paste to the grid at a substantially predetermined volumetric flow rate.